I don't read Young Avengers but if Young Avengers was even half as good as Uncanny X-Force, and there were already 5 Avenger movies with no sign of developing MS Marvel I would see absolutely nothing wrong with it.

Well it sounds to me, that you'd be fine introducing Wolverine in a New Mutants movie, Cyclops in a X-Factor movie and Iron Man in a West Coast Avengers movie (or what spin-off they have) as long as the material in the comic-books are good or they had a good run in the comic-book. And if the main movie series still haven't use them.